TPB added to TRA because TRA components may not be sufficient to explain behavior in which volitional control is reduced
- Behavior
- Perceived behavioral control
- Control beliefs
- Perceived power
Perceived behavioral control
Definition(s):
- The extent to which a person feels able to enact the behavior
- A function of an individual's control beliefs and perceived power with beliefs
Example:
- Prospective study concerning exercise among pregnant women, baseline question: "For me to exercise during my second trimester of pregnancy will be"
- Followed by a 7 point extremely difficult / extremely easy response scale
Control beliefs
Definition(s):
- Beliefs about the presence of factors that may facilitate or impede performance of the behavior
- Contributes to perceived behavioral control along with perceived power
Example:
- Prospective study concerning exercise among pregnant women, baseline question: "If I wanted to, I can easily exercise during my second trimester of pregnancy"
- Followed by a 7 point strongly agree / strongly disagree response scale
Perceived power
Definition(s):
- Beliefs about the power of situational and internal factors to inhibit or facilitate the performing of the behavior
- Contributes to perceived behavioral control along with control beliefs
Example:
- Prospective study concerning exercise among pregnant women, baseline question: "How much control do you have over exercising during your second trimester of pregnancy?"
- Followed by a 7 point very little control / complete control response scale